The invention relates to a device for placing an object in which the object is placed on brushes, whereby a first part of the brushes and a second part of the brushes alternately maintain contact with a surface of the object.
On machines such as e.g. machine tools, production machines or robots that process objects such as e.g. plates, different possibilities are known for placing objects. In a frequently encountered placement possibility, the objects are placed on brushes.
FIG. 1 shows such a common placement of an object, that in the example in FIG. 1 takes the form of a plate 1. The plate 1 is placed in the normal manner on brushes 3 that are connected to a machine bed 2. The brushes here have contact with a surface 4 of the plate 1. The contact between the plate 1 and the surface 4 of the object 1 results in an adhesion during transport of the plate 1 by a drive mechanism (not illustrated for the sake of clarity) at the travel speed v, that in conjunction with the weight FG of the plate 1 causes a bending of the brushes 3.
FIG. 2 shows such bent brushes 3 that result when the plate 1 is drawn over the brushes 3 at a speed v. In FIG. 2 the same elements are indicated with the same reference numbers as in FIG. 1.
The placement of the plate 1 on such bent brushes 3 has certain disadvantages. The object, i.e. in the illustrative embodiment the plate 1, can move easily due to the bent brushes 3, in particular in a horizontal transverse direction relative to the bending direction, whereby the bending direction in FIG. 2 is identical with the direction of the speed v. This leads to instabilities and poor guidance in the transport of the object during a machining process on the object. This leads to a poor machining quality of the object. The constantly changing friction conditions that depend e.g. on the extent of bending of the brushes 3 also lead to a deterioration in the positioning accuracy of the object. The abovementioned problem is further exacerbated if the direction of the travel movement of the object is reversed or changed during the machining process.
A device for the alignment of flat objects transported in a continuous series is known from German laid-open specification 197 10 630 A1. In order to reduce the load and hence the wear on the brushes due to fluctuating thicknesses of the specimens and to permit delicate alignment of the specimens in transport direction, each brush is supported in a spring-like manner by a working cylinder with variable pressure.
A device for computer-controlled precision cutting of plates with a bristle table is known from the European laid-open specification 0 972 600 A2.
A transport device for plates is known from European laid-open specification 0 482 702 A1.
A coordinate table for positioning of workpieces such as e.g. sheet steel billets relative to the workstation of a punching machine is known from European laid-open specification 0 338 132 A2.
A device for supporting and transporting steel plates during machining in a punching and/or cutting machine is known from the European laid-open specification EP 0 482 702 A1.
A coordinate table for a punching machine, consisting at least of one workpiece supporting surface resting on a frame with bristles protruding out of the workpiece supporting surface in preferably uniform distribution that together form a workpiece supporting plane is known from German utility model DE 88 05 081 U1.
A device for discontinuous transport of rod-like workpieces, in particular solid sections and tubular sections, laterally to the direction of movement on a transport track with at least one transport standstill is known from the German utility model DE 200 00 583 U1, whereby at least on one side of the transport track or at the face end of the workpieces the device has at least one device for machining and/or coating and/or cleaning and/or measurement that is active only during at least one transport standstill.